Here’s a complete pack containing all necessary Recalbox and Batocera bios files.
You just have to paste all the files in the bios folder. Only exception for the “neogeo.zip” file which needs to be placed in roms/neogeo folder. I’ve modded the Neo Geo bios with the unibios so you can play the games in AES, MVS or UNIBIOS mode. AES is the home console version of the bios allowing you to change difficulty and no coins are needed to play. In a game just press the Option Key + X and it’ll open the RetroArch menu. Change the bios to your liking and reboot. You can also hide the neogeo.zip entry in your game list because it’s not a game.